Hoe smaakt het? Nieuwe inzichten uit de wetenschap van ruiken en proeven.

Uitgeven van mijn populair wetenschappelijk boek. Hieronder een blurb:
Koken en eten staan zeer in de belangstelling. Elke week komt er wel een nieuw kookboek uit en regelmatig verschijnt er een chef op tv met een nieuw kookprogramma. Veel mensen hebben plezier in koken als hobby en besteden hier veel tijd aan. Al hun inspanningen zijn erop gericht om lekkere gerechten te bereiden, gerechten die onze tong ‘strelen’. Maar wat is dat nu precies, ‘lekker’, en hoe worden onze zintuigen eigenlijk ´gestreeld´?
De smaak en de reuk behoren tot de zogenaamde chemische zintuigen. Dit wil zeggen dat ze reageren op de moleculen waarmee ze in aanraking komen. Iedereen weet wel iets over het netvlies of over kleurenblindheid maar de werking van de neus en de tong is relatief onbekend. Wist u bijvoorbeeld dat het ‘proeven’ voor het grootste deel door de neus wordt gedaan? Dat je veel meer geuren kunt ruiken dan kleuren kan zien? Dat je niet kunt merken door welk neusgat je ruikt? Maar ook dat je onbewust luistert naar je voedsel?
In dit boek worden de reuk en de smaak behandeld, maar ook het zien, het horen, het voelen en nog meer, vaak onbekende, zintuigen die een grote rol spelen bij het eten. Hiernaast zijn er veel psychologische factoren die een effect hebben op wat u proeft. U leest over voeding, u ziet reclames, u googelt en u praat erover met anderen.
Hoe u denkt over wat u eet blijkt net zo belangrijk als wat u proeft. 'Lekker' zit meer in de eter dan in het eten.

Smelly and Dirty: Valence, not semantics, of odours affects cleaning behaviour

Finalising our paper.

Dijksterhuis G.B., Zandstra E.H., Smeets M.A.M., De Wijk R.A.


Odours typically associated with cleaning products, such as citrus, have been reported to activate cleaning behaviours. The aim of the present study was to test whether odours in general or pleasant odours specifically, would also do so. Furthermore, the identifyability of the odour might be expected to play an important role: it is known that clearly recognisable odours lead to fewer behavioural effects than odours that are barely noticed. We used three odours: clearly unpleasant (Sulphur), clearly pleasant (Orange) and a rather neutral somewhat less familiar one (Grass). Naïve participants visited four special odour-controlled rooms for what they believed to be a food product test. In each of the rooms one of the odours was dispersed at a time. Participantswere requested to cut a rusk into several parts, eat the parts, and then answer some questions presented on a computer screen. The behaviour of the participants was recorded on video, and scored by several independent assessors using a structured observation method for quantitative coding and description of the cleaning behaviours observed (e.g. sweeping crumbs from a table). The results show that different odour qualities appeared to trigger different levels of behavioural effects, and in particular that cleaning behaviour is not activated exclusively by a odour putatively prompting associations with cleaning products, like citrus odours. Green grass, not known for its association with cleaning, showed similar effects to Orange. We posit that odour valence plays an important role, as Grass -and Orange- are in general well liked and have positive connotations, and produced more sweeping movements than the unpleasant Sulphur.

NOSE: Netherlands Olfactory Science Exchange

Aiming to attract more attention to the scientific study of olfaction. I'm part of the steering committee, together with prof Asifa Majid, prof Monique Smeets, dr Sanne Boesveldt, dr Jasper de Groot, dr Laura Speed, Caro Verbeek.

The scientific study of the perception of odours is suffering. It's still often seen as an exotic topic, very applied, and perhaps not worthy of serious investigation. This view may partly arise from not understanding the olfactory system. We aim to change all this, by organising meetings, attracting attention, and any other means. Olfaction is one of the most complex sensory systems we have, both physiological (e.g. it has 350 different receptor types) as well as psychological (it's almost impossible to find words for odours, and many behavioural effects arise from inattentive perception of odours).

When the NOSE website will be made available, I'll let you know here!

  • White Taste

    Does the concept of a White Taste exist (or make sense)? This work is inspired by the work on 'White Odour' by Weiss et al. (2012) and carried out in cooperation with Dr. Sanne Boesveldt, and Karen de Rosa Spierings (WUR).
    Weiss, T., Snitz, K., Yablonka, A., Khan, R. M., Gafsou, D., Schneidman, E., & Sobel, N. (2012). Perceptual convergence of multi-component mixtures in olfaction implies an olfactory white. Proceedings of the National Academy of Sciences, 109(49), 19959–19964.

  • Dwarskoken: Vijf stellingen ter bevordering van een discussie over de ‘optimale eetbeleving’. (met 'creative Chef' Jasper Udink ten Cate)

    Hieronder vindt u vijf stellingen om over te discussiëren. We hebben ze opgesteld om nieuwe ontwikkelingen in de gastronomie mogelijk te maken. We hebben de regels in nogal sterke bewoordingen opgesteld om discussie uit te lokken.
    1. Moleculaire gastronomie is voorbij.
    2. Authenticiteit en natuurlijkheid zijn lege begrippen.
    3. Het streven naar lege labels is onzinnig.
    4. Er bestaan geen ongezonde producten.
    5. U bent niet allergisch voor voedingsmiddelen.

Are effects of aromas psychological or physiological (or both)?

A overview paper I've written with Bart Ferguson and Monique Smeets.

In aromatherapy, essential oils are administered to improve health and mental well-being. As it is at present not entirely clear how to account for these effects, two different mechanisms have been proposed, namely a psychological and a pharmacological mechanism.

There is a general consensus among scientists that the psychological mechanism is a viable and potent one, and probably the major route for successful aromatherapy. In contrast, the pharamacological route is regarded as problematic. However, a systematic overview of what the pharmacological mechanism for aromatherapy affords seems to be lacking.

The aim of the present overview is to systematically address, from the perspective of pharmacology, what it would entail for aromatic compounds to achieve beneficial effects on body or mind. The focus of the overview is on the pharmacokinetic and pharmacodynamic properties (e.g. including the well known ADME-model) of the compounds involved, that would be required for such mechanisms to be seriously considered.

We will illustrate evidence for either mechanism with a brief overview for sweet orange, consisting mainly of d-limonene and beta-myrcene, with purported anxiolytic effects. We end conclude by formulating a roadmap, requiring a multidisciplinary approach, for research into the pharmacological mechanism of aromatherapy, needed to substantiate its claims.

Olfactory Transmission: what's needed and what's possible?

Accepted abstract for: http://meaningculturecognition.ruhosting.nl/news-events/events/human-olfaction-at-the-intersection-of-language-culture-and-biology/

Pictures (including movies) and (live) sounds are transmitted through tv-channels and over the internet easily and virtually instantaneously. Why don’t we transmit other sensory information, e.g. from touch, taste or smell?

We will argue that the latter group of ‘near’ sensory systems possess characteristics that make them different from the 'far', viz. visual and auditory senses. We will compare the visual, auditory and olfactory senses on a number of criteria. We will address technological issues, a viewpoint concerning the reality value of transmitted odours and an information theoretic stance. In addition we'll try to imagine what it takes to be able to transmit odours with enough resolution and validity to evoke at the receiving end, what they did at the sending end.
We conclude that it is currently not feasible to transmit odours, e.g. over the internet. Both at the sending and the receiving end technological and reality problems need to be solved that cannot be solved today. Maybe the nature of odours is such that it will prove fundamentally impossible to reliably transmit them. One important problem is that odour perception is largely dependent on expectations, there is no unique correspondence between an odorant and an odour experience. Another is that odours mainly convey emotional information, depending on context. Devoid of a context an odour loses its meaning. What is left after it is transmitted, if at all possible, is a meaningless sensation.
Applications in a VR-context, i.e. with only a receiving end, so no ‘transmission’ really, seem to be feasible. A science of application of odours conveying their emotional meaning may work in gaming or other comparable applications.

Garmt Dijksterhuis12, Per Møller2 
1Amsterdam University of Applied Sciences, the Netherlands
2University of Copenhagen, Denmark.

Guest Associate Editor Frontiers in Psychology

section: Theoretical and Philosophical Psychology

research topic: The Impact of Psychology and Neuroscience on Theories of Identification and Liking in the Humanities

Many recent studies have shown how the mainly humanities domains of (i) culture, e.g. literature, poetry, painting, dance, theatre, music, sculpture, and (ii) communication, e.g. language, media, rhetoric, can benefit from mainstream and emerging psychological, cognitive and neurobiological insights, arguments, and methods. Numerous avenues have been explored including neurocognitive poetics, cognition and music, neuro-aesthetics, etc. Two related thematic areas that arguably warrant further and deeper investigation pertain to the concepts of ‘liking’ and ‘identification.’ This will be the focus of this Research Topic. 

We all have preferences, some things we like, others we don't, some people we love, while hating others. This is such a universal phenomenon that we hardly devote time to realising how important it is. The underlying psychological processes we let automatically make decisions for us. They guide our behaviour and our choices, actually they make – or break – our lives. The concepts of liking and identification are equally relevant to cultural objects like protagonists that appear in novels, iconic art works or landmarks, and also to components in communicative processes, like the Aristotelian notion of ethos in classical rhetorical theory. 

This Research Topic will be approached from a number of disciplines. We call for theoretical and empirical contributions from linguistics, rhetoric, perception psychology, emotion psychology, cognitive science, embodied/situated cognition and phenomenology. We can think of a range of cultural and communicative application areas where issues of liking and identification can be studied within a cognitive and/or neurocognitive framework including literature, the visual arts, music, dance, past and present material culture, speech making, news/political discourse, consumer products, advertising, food, etc. The roles of consciousness and non-consciousness, emotion and cognition, and memory, motor action and perception will undoubtedly be of significance in the papers that will appear in this Research Topic.

Keywords: cognitive science, communication, culture, embodied cognition, emotion, identification, liking, linguistics, mind, perception, phenomenology, rhetoric, situated cognition


The music smells can make...

For this project we're still looking for a GC/MS (with 'nose') that someone is happy for us to use. Perhaps an obsolete one can even be donated. See the plan in the schematic.

A less expensive option would be an 'electronic nose' or other 'sniffing' device. Please let me know if you can spare one.

NUDGIS: Nudging for healthy choice: Novel Understanding of Designs for Good Intervention Strategies in the food environment.

The NUDGIS research program examines the effectiveness of nudges, defined as subtle rearrangements of the choice context, to gently suggest healthier food choices by taking advantage of previous priming research to influence healthier choices in such a way that they do not rely on effortful decision making. Although the priming literature suggests several mechanisms that may explain in what way subtle environmental cues influence such complex behaviour as food choices, most priming research has been conducted in single lab studies, precluding an assessment of their effectiveness and robustness outside the lab. The program acknowledges this limitation and specifically addresses the maintained effectiveness of subtle rearrangements in complex setting. The program entails four projects, addressing (1) the role of social context and (2) emotions as nudges in lab settings and real life contexts by employing lab studies, community studies, and fMRI studies; (3) the role of awareness and salience of nudges to examine their impact on autonomy and motivation for healthy food choices and the potential negative side effects is behaviour is influenced without having a clear understanding of its cause; and (4) robustness and long-lasting effectiveness of multi-cue nudges that influence food choice by multiple pathways. As a whole, the program will contribute to our understanding of the working mechanisms of nudges by incorporating notions from the priming literature and examining them in context. The program will result in the formulation of rules to design effective nudges that help to make the healthy choice the easy choice.

  • Ghost writing

    I'm involved in writing some texts in the general area of food and flavour. I deliver commissioned text as a 'ghost writer'. This means that I may not appear as an author but receive an agreed fee for a certain word count.